- "You're going to save us!"
- —Penny Peterson
Penny Peterson is is the daughter of Paul and Patty Peterson and the tritagonist of Mr. Peabody & Sherman.
Blonde hair, blue eyes, wears a pink dress, white socks, and black shoes.
Penny is a serious girl for someone of her age. Penny is very rich and spoiled. She appeared to have been envious of Sherman's smarts and called him a dog and bullied him which resulted into a fight. She may also have a wicked sense of humor and spiteful as she would go far to get back at those she dislikes, as she bullied Sherman and in Egypt, when King Tut threatens to kill Mr. Peabody and Sherman, she says "You'd do that for me?", indicating she may have wanted that to happen out of spite for Sherman showing her up in class. However, later they form a very strong friendship during their adventure.
Despite all of this, she is also shown to be willing to face up to her mistakes, as she proclaimed in front of everyone that it was her fault for provoking Sherman to bite her and that he didn't do anything wrong and attempts to take full responsibility for her actions in order for Mr. Peabody and Sherman to remain together(though this is not enough to convince the cold-hearted Ms. Grunion to release Mr. Peabody) and apologizes for everything she has done. This proves not only can she understand her own mistakes, but is also loyal and caring to those she is close to.